This invention relates to a method for producing a slideway-type guide for driven chains, in which the guide is provided with an at least partly curved slideway on which the chain runs, and in which a running surface made of a wear-resistant hard metal alloy--particularly, a hard cobalt alloy--is applied to the slideway, at least where there is a direction-changing surface.
Driven chains are used in various fields of technology (e.g., traction mechanism, cutting chains and for many other purposes). For many applications, chains have to slide on a guide surface with a change in direction. Depending on the tension of the chain, and the power to be transferred or applied by the chain, the slideway of the guide is often subjected to great stress, which can result in considerable wear to the guide itself and to the links of the chain sliding on the guide. It is therefore customary to apply a wear-resistant hard metal alloy running surface to such highly stressed guides, particularly where they change direction. One of the hard cobalt alloys or nickel-based alloys of various compositions, known by the trade-name Stellite, can be used. Apart from cobalt itself, hard cobalt alloys also contain other metals, e.g., nickel and/or chromium, as well as other components. A basic nickel alloy is Stellite 453.
The structure of the Stellite alloy used for the running surface varies depending on the manufacturing process used to make the blanks for the running surfaces. If the blank is made from rolled sheet metal, it has a rolled structure containing individual spheroidal carbides, as a result of which the running surface can withstand Great forces, particularly compressive forces, without being damaged. These running surfaces are therefore highly wear-resistant, but are expensive to manufacture. It is more cost-beneficial to produce the blanks by continuous casting (strand casting) or suction casting, or by metal-powder injection molding or sintering of Stellite, in which case the blanks can be formed as round or flat, profiled bars. With this production process a dendritic structure or "weld structure" containing cavities and acicular (i.e., needle-like) carbides with a lattice structure is formed. After appropriate forming and bonding to the slideway, running surfaces formed from such blanks are also very wear-resistant as far as abrasion is concerned, but their structure cannot withstand high pressures. When the slideway is subjected to more or less perpendicular pressure, individual acicular carbides can break, and, when the slideway is in constant use, the acicular structure can be partially destroyed due to compressive stress, finally leading to breakouts in the running surface.
It is therefore an object of the present invention to provide a slideway-type chain guide produced economically and in such a way that the running surface is highly wear-resistant, even when subjected to high compressive stress.